jm + autonomous-vehicles   2

Autonomous Precision Landing of Space Rockets - Lars Blackmore
from 'Frontiers of Engineering: Reports on Leading-Edge Engineering' from the 2016 Symposium, published by the National Academies Press, regarding the algorithms used by SpaceX for their autonomous landings:
The computation must be done autonomously, in a fraction of a second. Failure to find a feasible solution in time will crash the spacecraft into the ground. Failure to find the optimal solution may use up the available propellant, with the same result. Finally, a hardware failure may require replanning the trajectory multiple times.

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Suggested Citation:"Autonomous Precision Landing of Space Rockets - Lars Blackmore." National Academy of Engineering. 2017. Frontiers of Engineering: Reports on Leading-Edge Engineering from the 2016 Symposium. Washington, DC: The National Academies Press. doi: 10.17226/23659. ×

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A general solution to such problems has existed in one dimension since the 1960s (Meditch 1964), but not in three dimensions. Over the past decade, research has shown how to use modern mathematical optimization techniques to solve this problem for a Mars landing, with guarantees that the best solution can be found in time (Açikmeşe and Ploen 2007; Blackmore et al. 2010).

Because Earth’s atmosphere is 100 times as dense as that of Mars, aerodynamic forces become the primary concern rather than a disturbance so small that it can be neglected in the trajectory planning phase. As a result, Earth landing is a very different problem, but SpaceX and Blue Origin have shown that this too can be solved. SpaceX uses CVXGEN (Mattingley and Boyd 2012) to generate customized flight code, which enables very high-speed onboard convex optimization.
spacex  blue-origin  convex-optimization  space  landing  autonomous-vehicles  flight  algorithms 
8 days ago by jm
V2V and the challenge of cooperating technology
A great deal of effort and attention has gone into a mobile data technology that you may not be aware of. This is "Vehicle to Vehicle" (V2V) communication designed so that cars can send data to other cars. There is special spectrum allocated at 5.9ghz, and a protocol named DSRC, derived from wifi, exists for communications from car-to-car and also between cars and roadside transmitters in the infrastructure, known as V2I.

This effort has been going on for some time, but those involved have had trouble finding a compelling application which users would pay for. Unable to find one, advocates hope that various national governments will mandate V2V radios in cars in the coming years for safety reasons. In December 2016, the U.S. Dept. of Transportation proposed just such a mandate. [....] "Connected Autonomous Vehicles -- Pick 2."
cars  self-driving  autonomous-vehicles  v2v  wireless  connectivity  networking  security 
may 2017 by jm

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